The present invention relates to a water-base silicone composition or, more particularly, to a water-base composition containing an organopolysiloxane as the principal ingredient and suitable as a coating agent of rubber articles and fibrous materials to form a coating film thereon exhibiting excellent adhesion to the substrate surface and having excellent abrasion resistance and surface lubricity.
It is an established technology in the prior art that various kinds of rubber articles can be imparted with improved lubricity and abrasion resistance by coating the surface with a silicone resin composition. For example, Japanese Patent Publication 60-50226 discloses a method for the surface treatment of a rubber article with a composition comprising an organopolysiloxane having epoxy groups and an amino group-containing organosilane and/or organopolysiloxane. Further, Japanese Patent Publications 54-43023 and 56-47864 disclose a method for the surface treatment of a rubber article with a composition comprising an organopolysiloxane having hydroxyl groups with admixture of an organohydrogenpolysiloxane. Japanese Patent Kokai 7-109440 discloses a method of surface treatment with a composition comprising an organopolysiloxane having hydroxyl groups, an organohydrogenpolysiloxane and a hydrolysis-condensation product of an amino group-containing dialkoxy silane. Japanese Patent Publication 4-80072 discloses a method of surface treatment with a composition comprising a hydroxyl or vinyl group-containing organopolysiloxane, an organohydrogenpolysiloxane and a dimethylpolysiloxane. Japanese Patent Kokai 7-196984 discloses a method of surface treatment with a composition comprising a hydrolyzable group-containing organopolysiloxane, an organopolysiloxane containing epoxy or amino groups and hydrolyzable groups and an organosilane containing an epoxy or amino group and a hydrolyzable group. Japanese Patent Kokai 7-233351 discloses a method of surface treatment with a composition containing a hydroxyl group-containing organopolysiloxane, a hydrolysis-condensation product of an epoxy group-containing dialkoxysilane, a hydrolysis-condensation product of an amino group-containing dialkoxy silane and a fine powder of a silicone rubber.
When these silicone compositions prepared by the above mentioned prior art methods are used for surface treatment of a rubber substrate, however, the coating layer formed therefrom is defective in the poor adhesion to the substrate surface and insufficient abrasion resistance and surface lubricity so that development of a novel silicone-based composition free from these disadvantages is eagerly desired.